Siamcbnts



Nov. 6, 1928.

c. THOMPSON Re. 17,127

5 Sheets-Sheet 1 SHOCK ABSORBER ()Wnal Filed April 14, 1924 I c. w. THOMPSON Nqv. 6, 1928. SHOCK ABSORBER Re.- 17,127

' I 3 Sheets-Sheet 2 Origipal Filed April 14, 1924 IHIH- anon 11b7,-

Nov. 6, 1928 c. w. THOMPSON Re 17,127'

SHOCK ABSORBER 5 Sheets-Sheet :3 Original Filed April 14, 1924';

AK. Miami,

eau nmwa v 'Re.i7,-127 YUNITED sTA'r s- PATENT 1 OFFICE.

snocx ansonnnn.

cum-1 Io. 1,502,012, am m an, 1920, Serial Io. 700,412, fled r m 14, 19. Application 101- reissue ma M1718, 1m. Serial Io. aaapeaz The device provided b the invention is ig. 4 is a section illustrative of an alter l6 formed and arranged so t at it ofiers resist native form of valve member; ance to spring compression between the load Fig. 5 1s a longitudinal section illustrative and runninggear of a vehicle, and restrains of 4 alternative form of casing l with greater resistance the upward rebound Flg. 6 is a section illustrative of another.

of the load after spring com ression. The form of valve member; 1 device is intended primarily or association Fig. 7 is a section illustrative of another with motor-vehicles, but it also is adaptable form of stop member; and v to other uses. ig. 8 is a view of an installation of the 10 More specifically, the invention pertains to device.

devices of the type that comprise a piston The device includes an elongated casing 9, 6b acting in a casing a ainst fluid therein. which preferably is of cyhndrical form.

It is an object of t e invention, not only so When of the type disclosed by Fig. 1, the casto form and arrange the parts that more remgs may be produced by severing required sistance is offered to piston movement in one lengths from tubular stock and by screw direction than in the other, but also to ofler threading the pieces exteriorly at one end 70 more resistance to piston movement near the and interiorly at the other. 7 I I ends of the casing than when the piston is in The casing is closed at one end by a cap 10 intermediate position whereby sudden stopprovided with a port, closed by a plu 11,

page of relative movement of the casing and through which the device'may be charge. and

piston and of the parts connected therewith is drained of liquid; The cap includes a sleeve prevented. v I p 12 screwed onto the exteriorly-threaded end Further, it is an object of the invention'to' of the casing. The sleeve hasan interior anassociate with piston-, rts a valve member so nular abutment or shoulder 13, which bears arranged that it will eave the ports open on against the end. of the casing when turned movement of the piston in one direction and down thereagainst, and a gasket 14 may be ininstantly restrict fluid flow therethrough on ter sed between the abutment and casing commencement of movementin' theopposite en to afford a fluid-tight joints The cap direction, l contains a chamber located beyond the end of It also is a purpose of the invention to the casing. The interior. diameter of the improve details of construction and arrangecap-sleeve is slightly greater than that of the ment of parts in devices of this sort. casing, so that the casing end afiords an in- When considered in connection with the de terior annular abutment or seat' 15 at the end scription herein, the characteristics of the inof the sleeve-chamber for a purpose herein- 35 vention are apparent from the accompanying after explained. 1 I I di'awings,' forming part hereof, wherein em- Thecasing of the form exem lified by Fig. bodiments of the invention adapted for use in- 1 is closed at its other end by a plhg 16 screwed motor-vehicles are disclosed, for purposes of thereinto and having an exterior abutment or illustration. 4 p e g against a gasket 18 be- Although the disclosures herein exemplify tween 1t and the casing end to provide a fluidwhat now are considered to be preferable emtight joint. The plug contains a stufling box 05 bodiments of the invention, it is to be under- 19, which extends inwardly of thecasing bestoodthat it is not the intention to, be limited yond the body of the plug and terminates in a necessarily thereto in interpretation of the centrally positioned annular abutment or 45 claims, as modifications and adaptations wall 20. 1 within the limits of the claims canbe made The casing also-may be a hollow casting of without departing from the nature of the ina form exemplified by Fi 5. In that form it vention. V has near its exteriorlyreaded end an anfiiLike reference-characters refer to correnular abutment or shoulder 13, on which is 7 spending parts in the views of the drawings, a gasket 14, against which the end of the ca of which sleeve 12 is turned to provide a fluid-ti t I Fig. 1 is a; longitudinal section; joint. The other end portion of thee is t Fig. 2is 880121011 on the line 22,Fig. 1; enlarged, as shown at 21, and a stufing Eox Fig. 3 is a sectionon the line 33, Fig. 1; iof substantially the same form as that disof less diameter extending therefrom closed by Fig. 1 is formed integrally with the casing wall. v

A piston-rod 22 is reciprocable in the stuffing-box and extends into the casing. It has on its inner end portion an annular shoulder or seat 23, a part 24 of less diameter extending therefrom, an annular shoulder or seat 25 on that part, and a threaded terminal 23 an carryin anut 27.

A ho ow i'ston or stress-sustaining member 28 is reciprocable in the casing and has close fit with the side wall thereof. The piston includes anup er disk-like wall or head 29 having a centra opening of substantially the size of the threaded piston-rod terminal 26 and through which that terminal extends. The nut 27 holds the piston on the-rod and the iston-head against the shoulder 25. Equa ly s paced ports 30 extend throughthe head in clrcular disposition. A floatin valve member 31, substantially of washer-l1 e flat form, is movable freely on the reduced part 24 of the piston-rod between the shoulder 23 and the piston-head, which arts limit its sliding movement. I is ormed to seat closely against the head and in that position to close the major area of the ports 30 and thus restrictor reduce the, area of the ports available for fluid flow therethrough. The member 31 may be formed in any one of several ways to leave open part of the area of the ports 30 when it is. againstthe head.

For example, the member 31, as shown by I Fig. 2, hasa segment omitted or out therefrom along linea,which is so coordinated with a respect to the circularly-disposed ports 30 ment of that mem that, when it is tangentto the inner 'side of one of them, itis about tangent to the outer side of an adjacent port. Thus the area of one ort is uncovered by the valve member,

and it is unnecessarflto prevent rotary mover; for, if the member turns and begins to cover one port, it at the same time will uncover an approximately equal area of another port. In view of the fact that it is unnecessary to spline the" member 31 on the piston-rod or otherwise prevent 1ts rotation, it is freely movable on the rod and is'not apt to become caught either in or out of port-closing position. It is to be understood, of course, that, if desired, thevalve member may be formedfso that it will leave more than one port or the area of less than one port uncovered, the amount of uncovered area being de ndent upon the size of. the segment omit or cut from the member.

The valve member also may be formed with ports 32 so relatively di osed'with re-i spect to the spacing of the hea -ports 30 that one of them comes mto alinement with one of the latter ports as another moves therefrom, as shown by 4. v In still an or form, as exemplified by Fig. 6, the valve member 31 is of such diameter that its periphery intersects the periphcries of the ports .30, and thus leaves a part of all of those orts uncovered and open.

, The piston a so includes-a side wall or skirt 33 integrally formed with and extendin from the head 29 toward the stufiing-box en of the casing. That wall closely fits the easing-wall, and it comprehends a chamber open J at one end and havin the ports 30 communion the end wall or abutment 20 of the stuflingbox. A member comprising a collar 35 and a head 36of disk form is slidable on the piston-rod 22. It bears at one side against the spring34, and its head is arranged to move into the piston-chamber and to have close fit with the wall 33. The head is formed with ports 37, for a purpose hereinafter explained.

A stop member 38 of flat-ring form and having an annular flange 39 at its outer periphery is slidable in the chamber of the cap in fairly close contact with the wall of the sleeve 12, the flange being provided to restrain'the member from tilting. The member v38 yieldably is held on the seat 15 by a compression-resistive coil-spring 40 interosed between it and the head of the cap. he stop member, when of the form disclosed by Figs. 1 and 3, is arranged to cover'and c ose all of the ports 30 whenthe head of the piston comes into contact therewith. The stop member also may be correlated with respect to those ports insuch manner that part of the ort area is left open when it and the pistonead come together; as, for example, by makin the interior periphery of the member of suc diameter that it intersects the perigiheries of the ports 30 and thus leaves part 2 th; area of e portsopen, as shown by The casing is char (1 with an suitable fluid, such, for examp e, as oil or alcohol, the

viscosity and other characteristics of the liquid employed being determined by the conditions to be encountered in service and the sensitivenes it is desired to have in the deresistance to heavy fluid-t an with light.

two relatively movab e parts, as with the runnmg-g'ear and with the crown of a vehiclesprlng sup orted there0n.' 'For example, as

own by- 8' the 'casing-ca and istonrod jjnay be p P i "gar-med withballs which are vice, it'being understood, of course, that more piston movement is offered with 1 and the spring 40 in the cap-chamber, and that movement stopped. Even with the maximum thrust that may be liable to be imposed on the device, piston movement is stopped by r the associated with sockets of members B and C ture D and a y member E. stallation is disclo d cation, as the device will function satisfacto'rily when in a substantially vertical position the reverse of that shown and when installed in horizontal or inclined positions.

The several-parts preferably are coordinated in such manner that, with the usual conditions of load and roadway, the pistonhead is at, or about at, a position approximately midway between the ends of the casing, as shown "by Fig. 1, where it is out of corxgilration with the head 36.

en a vehicle equipped with one or more of these devices is in motion and the runningt rust'toward each ot or as a result of irregularities in the roadway or other causes incident to operation, the piston and cap of each device move toward each other. During such movement, fluid in the casing asses freel of position to the inside of the-piston, pressure keeps the valve member 31 in 0 on the shoulder 23, fluid flows periphery of wall 33, and the piston only encounters such resistance to'movement in that direction as results from friction and the forcing of the fluid from one side of the piston to the other.

If the thrust force is of such extraordinary amount asto be suflicient to brin the pistonhead and the stop member 38 1nto contact, that member entirely or partly closes the piston-ports, dependent u on whether it is or the form of igs. L an 3' or that of Fig. 7 and greater resistance is'ofiered to further movement by the cushioning action of fluid the spring 40 when it closes and thus reaches the imit of its compression, if it is not sto' ped before b by rostatic or asaction. 1 n cessation o thrust of load an {runningof rebound or movement in the opposite direction under the influence of springs supporting the load on the and cap move away ite-dimotion through the piston-ports. instantly moves the valve member against iston-he'ad-and closes the ports thereof to t e extent it is" arrangedto close them. Accordingly, more. resistance is 'afiorded. to

-' movement Ill $11M; direction than in the thrust direction, and rebound action in the vehicle is. snubbed. Even after slight thrust action with comparatively slight movement of the piston, on commencement of. a corresponding action the valve once connected, resggcgzively, with an axle. struc-.

Such an inmerely for exemplifi {member and those ton-ports 30 ear and a load sprin supported thereon are,

through all of the ports 30 from the oufii stween-the that member and the piston-- -36, that head is gear toward each other and commencement running-gear, the lston' from each other an fluid v in the casing tends to flow in the op I e' fluid view of the comes into closing relation to the ports andreaction is restrained.

If the rebound fluid pressure until the head and valve mem-' the ports 37 in the head 36 is cleared from between the head and the valve parts are permitted to with the valve member ports 37. Then the pis are entirely closed by the head and appreciable further rebound movement checked by the cushioning action of fluid and of the sprin 34, the amount of such movement when t e device is charged with liquid being only that that may be ermittedby slight leakage around port-c osing. parts.

through quick y come close together, entirely closing the force is sufiioient to bring the head 36 into the piston, increased resist- 1 ance to piston movement results from contact 10 of that head with the piston-wall 33 and fronr Even with the most forceful rebound action that may be liable to be imposed on the device, piston 'movement is stopped b the spring. reaches the limit of its compression, if it is not stopped before byhydrostatic or gas action.

After cessation of rebound action, andwhen the load begins to'settle down toward normal position against its sprin supports on the running-gear, the piston an cap move toward each; other as the do in response to thrust action, and under t e influence offluid action the valve member moves from contact with the piston-head toor toward. the shoulder 23, and all of the ports 30 are 0 view of the tendency of the fluid during movement of the valve member toward the shoulder 23 to seek the ports 37 of the head separated thereby from the valve member before the valve member reaches the seat, and during further movement' 'of the piston that head is forced by fluid out of the piston as the latter ap: proaches normal position.

A device constructed any er resistance near the limits of movement in 34 when it becomes closed an thus ened. In

in aooord'ancewith of the exemplifications herein disclosed functions efliciently to resist relative move-.

either direction than when the piston is in i intermediate position whereby sudden. sto

page ofmovement is avoided. Moreoveryt e arrangement of valve" member and associated parts provided by the ther motion in that direction is stop member to port-restricting position, rebound the invention is such that there is instant restriction of flow of fluid and increased resistance to movement when the pistonsta-rts motion inone direction (as in rebound) and later there is practicallyaction is restrained even after slight thrust action. v

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is

1. A shock-absorber comprising a casing,

7 flow of fluid through said ports, there being a paszage from one side of said valve member to the other, and a member slidable on said rod in contact with said piston-wall into and out of contact with said valve member.

2. A shock-absorber comprising a casing,

a rod reciprocable therein having a shoulder,

a. hollow piston including a side wall and a head having ports. connected to said rod, a valve member'in said piston freely movable on said rod between said shoulder and head arranged to contact with the'latter and restrict flow of fluid through said ports, there ing a passage from one side of said valve member to the other, and a member, having a port, slidable on said rod in contact with said piston-walLinto and out of contact with said valve member.

3. A shock-absorber comprising a casing,'a rod reciprocable therein having a shoulder, a hollow piston including a sidewall and a head having orts connectedto said rod, a

valve member 1n said piston freely movable on said rod between sai shouder and head arranged to contact with the latter and to cover,

H ports, ,there being a. passage from one side of sad valve member some of the area. of said to the other, a member slidable on said rod' "in contact with said iston-walliilto and out of contact with sai valve member, and a spring against which said latter member bears on its side opposite to said piston-head.

4. In a shock-absorber, the combination of a casing havin a seat therein, a rodgeci rocable insaid casinghavinga shoulder,a"ho low pistonincludin a side wall and a head having ports connect to said rod,,'a valve member In said piston freely movable on said rod between said shoulder and head arranged to contact with. the latter and restrict flow of fluid through said ports, there being a passa e from one side of said valve member to t e other, a membersslidable on said 'rod in contact with said piston-wall into and out of contact with said valve member, a spring against which said latter member bears on its side fiepposite to said pistomh'ead, a movable stop. v

member normally resting on said seat in the path of moveiiient of said piston-head arranged to contact therewith on the sideop 0- site to said valve member and restrict ow offluid through said ports, and a spring yieldpiston including a'side wall and a said piston, and means disposed ,ton mounted upon said piston;

5. .A shock-absorber, com rising a cylinder adapted to be substantialy Med with liquid,

0. rod reciproc'able within said cylinder, a iston mounted upon said rod and fittin wit in said cylinder and having ports ther'et rough, valve means associated with saidpiston and effective during relative movement between said piston and cvlinder in onedirection to permit passage of liquid throu h said ports and during relative movement iietween, said piston and cylinder in the opposite-direction of fluid past at one end of said cylinder adapted toward. the limit of to materially restrict passage possible relative movement between the.pis-' ton and cylinder in the first-mentioned direction to co-act with said piston to substantially entrap a body of liquid between the piston and cylinder end, said meansbeing formed to permit a restricted escape of such entrapped liquid.

6. A shock-absorber, comprising a cylinder adapted to be substantially filled with liquid, 0. rod reciprocable within said cylinder, a isrod and fitting witliin said cylinder and having ports therethrough, valve means associatedwith said piston and effective durin relative movement between said piston an cgllinder in one direction to permit passage 0 and during relative movement piston and cylinder in the opposite direction to materially restrict passage of fluid past said piston, and means dis osed at one end liquid throu 'h said ports" etween said,

of the cylindr and arrange toward the limit of possible relative movement between the piston and cylinder in the first-mentioned direction to co-act with said piston to materially restrict the flow through said ports of liquid otherwise entrapped between the piston and qylinderend.

7. shock-absorber, comprising a cylinder adapted to be substantially filled with liquid, a rod recipro'cable within said cylinder, a piston mounted upon said rod and fittin within said cylinder and having ports theret rough, valve means associated with said piston and effective during relative movement between said piston and cylinder in one direction to permit pasage of liquid "trough said ports and during relative movement between said piston and cylinder in the opposite direction to materially said-piston, and a disc ,member disposed at one end of said cylinder in sucha osition as to engage with ,said piston towar the limit. of possible relative movement of the piston,

restrict passage of fluid past,

Ill

Ill

ton and cylinder end and to leave open a sufiicient partof such port area to permit restricted escape of such entrapped liquid.

8. A shock-absorber, comprising a cylinder adapted to be substantially filled with liquid,

' said ports and during relative movement between said piston and cylinder in the opposite direction to materially restrict passage of fluid past said piston, and an annular member disposed at one end of said cylinder and arranged toward the limit'of possible relative said piston and sage movement between the piston and cylinder in the first mentioned direction to co-act with the piston to cut oil a material part of the port area to restrict passage of li uid through the piston and provide a 'stron iquid resist- .ance to further movement of t e piston.

9. A shock-absorber,comprising a cylinder adapted to be substantially filled with liquid, a rod reciprocable within said cylinder, a piston mounted upon said rod and fitting within said cylinder and having ports therethrough, valve means associated with effective during relative movement between said piston and cylinder in one direction to permit passage of liquid throu h said ports and durin relative movement etween said piston and cylinder in the opposite direction to materially restrict pasof fluid past said piston, and means disposed at one end of said cylinder adapted toward the limit of possible relative movement between the piston and cylinder in the firstmentioned direction to co-act with said piston to substantially entrap a body of liquid between the piston and cylinder end, said means being formed to permit a restricted escape of such entrapped liquid, and being yieldable in the first mentioned direction of movement of the piston.

10. A shock-absorber,

comprising a cylinpiston and efiective during relative movement der adapted to be substantially filled with liquid, a rod reciprocable within said cylinder, a piston mounted upon said rod and fi ting within said cylinder and having ports therethrough, valve means associated with said piston and effective during relativegovement between said piston and cylinder in one direction to' permit passage of liquid through said ports and during relative movement between said piston and cylinder in the opposite direction to materially restrict passage of fluid past said piston, and an annular member spring held one end of said cylinder and arranged toward the limit of possible relative movement between the piston and cylinder in the first mentioned direction to co-act with the piston to cut off a material art of the port area-to re strict passage of iquid through the piston and provide a strong liquid resistance to further movement of said piston.

' 11. A shock-absorber, comprisin a cylinder adapted to be substantially filed with liquid-,a rod reciprocable within said cylinder, a piston mounted upon said rod and fitting within said cylinder and having ports therethrough, valve means associated with said piston and, effective during relative movement between said piston and c linder in one direction to permlt passage 0 liquid throu h said ports and during relative movement etween said piston and cylinder in the opposite direction to materially restrict passage of fluid past said piston, said cylinder being .formed with a se t ad acent one end thereof,- a member enga;b

spring between said mem er and the cylinder end, said member being thereby positioned to engage said piston toward the limit of possib e relative movement between the piston and cylinder in the first mentioned direction,

and being formed so'as to materially restrict the flow through said ports of liquid otherwise entrapped between the piston and cylinder end.

In testimony whereof I aflix my signature.

CLARANCE W. THOMPSON.

in apredetermined position at v ing said seat, and a 

